Dual porting serial ATA disk drives for fault tolerant applications

ABSTRACT

The present invention is directed to an apparatus capable of dual porting a serial advanced technology attachment (SATA) disk drive in a fault tolerant communication system, such as fibre channel. The dual porting apparatus includes two idle regenerators coupled to two serial master devices, a synchronization logic capable of synchronizing the communications between one of the idle regenerators and a third idle regenerator coupled to the SATA disk drive. Furthermore the dual porting apparatus may include an auto detector capable of enabling either of the first two idle regenerators, thus effectively switching between the two.

FIELD OF THE INVENTION

[0001] The present invention generally relates to the field of datastorage, and particularly to a system for utilizing serial disk drivesin fault tolerant multi-initiated applications.

BACKGROUND OF THE INVENTION

[0002] Data storage has become increasingly important as informationhandling systems become capable of handling and communicating more data.Currently, improvements to data storage systems are aimed at increasingthe amount of data and providing fault tolerant systems. While datastorage systems have become more efficient at handling large amounts ofdata in a fault tolerant manner, typically such fault-tolerant datastorage systems often are cost-prohibitive.

[0003] Expensive fault tolerant data storage systems therefore may notbe implemented in certain situations where their cost is not justifiedby the design application. As a result, information handling systemsoften are configured with lower cost data storage systems. One exampleof this cost savings measure is in the implementation of serial advancedtechnology attachment (SATA) disk drives in place of fibre channel diskdrives.

[0004] Current fibre channel disk drives are multi-ported and offerfault tolerant interfacing with external components. One of thedrawbacks of including a fibre channel disk drive in a system is thedrive's price difference. Presently fibre channel disk drives typicallyare between 3 to 6 times the price of a SATA disk drive, for acomparable storage capacity. Thus designers often may include a SATAdrive instead of a fibre channel drive in certain applications.

[0005] While serial disk drive offer increased cost savings over fibrechannel drives, the inherent single ported design are often a source offailure, thus, reducing the availability of data. It is this singlepoint of failure which may cause designers either to include costlyfibre channel disk drives or risk potential data loss.

[0006] Therefore, it would be desirable to provide a system and methodfor cost-effectively utilizing serial storage devices in a faulttolerant applications, thereby allowing for the utilization of more costeffective serial storage devices without the drawbacks inherent to asingle ported system.

SUMMARY OF THE INVENTION

[0007] Accordingly, the present invention is directed to an apparatusand method for implementing dual porting of an inherently single portedserial disk drive, such as a SATA disk drive. The inclusion of anapparatus of the present invention allows a single ported serial diskdrive to operate, in a fault-tolerant system such as a system employingfibre channel based communication without the previously experiencedfault drawbacks.

[0008] An apparatus for dual porting a serial disk drive of the presentinvention in the presently preferred embodiment is connected through theback panel of an information handling system utilizing a peripheralcomponent interface (PCI) to a first and a second SATA master controldevices which are operating in a fibre channel based communicationsystem. In the present embodiment the dual porting apparatus is includedin a disk drive canister board additionally containing a SATA diskdrive. Further by including the dual porting apparatus in the disk drivecanister board in the event of a failure the dual porting apparatus maybe easily replaced.

[0009] In a further embodiment the dual porting apparatus contains afirst and a second idle regenerator connected to a first and a secondSATA master device, respectively. The first and the second idleregenerators being capable of transmitting and receiving signals totheir respective SATA master devices. Included in the dual portingapparatus is a third idle regenerator connected to the first and thesecond idle regenerators. The third idle regenerator additionallyconnected to a serial disk drive, such as a SATA disk drive. The thirdidle regenerator is capable of receiving and transmitting signals to theserial disk drive. Further included in the dual porting apparatus issynchronization logic capable of synchronizing the transfer between oneof the first idle regenerator and the second idle regenerator and thethird idle regenerator.

[0010] Additionally, the dual porting apparatus, in contemplatedembodiments, is capable of receiving control signals, therebycontrolling which idle generator is enabled from a SATA master device.In further embodiments the apparatus for dual porting a serial diskdrive includes an auto detector capable of determining thepresence/absence of idle characters from the first and the second SATAmaster devices. Thus the auto detector may determine which SATA masterdevice is active and thus enable a single SATA master device at a time.

[0011] It is to be understood that both the forgoing general descriptionand the following detailed description are exemplary and explanatoryonly and are not restrictive of the invention as claimed. Theaccompanying drawings, which are incorporated in and constitute a partof the specification, illustrate an embodiment of the invention andtogether with the general description, serve to explain the principlesof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The numerous advantages of the present invention may be betterunderstood by those skilled in the art by reference to the accompanyingfigures in which:

[0013]FIG. 1 is an overview illustration of an exemplary embodimentwherein an apparatus for dual poring a serial disk drive in aninformation handling system;

[0014]FIG. 2 is an overview illustration of an exemplary embodiment anapparatus for dual porting a serial disk drive in a disk drive canisterboard;

[0015]FIG. 3 is an overview illustration of an apparatus for dualporting a serial disk drive with capability for accepting control signalfrom an external source.

DETAILED DESCRIPTION OF THE INVENTION

[0016] Reference will now be made in detail to the presently preferredembodiments of the present invention, examples of which are illustratedin the accompanying drawings.

[0017] Referring generally now to FIGS. 1 through 3, exemplaryembodiments of the present invention are discussed, wherein an apparatusfor utilizing single ported serial disk drives, such as SATA disk drivesin multi-ported fault tolerant applications are discussed. Faulttolerant storage systems such as fibre channel disk drives offerincreased functionality over SATA drives which are subject to a singlepoint of failure, thus reducing the availability of data to the system.

[0018] While fibre channel drives offer advantages over that of SATAdrives, the high cost of fibre channel drives continues to be a factorin overall utilization. For example, fibre channel disk drives are oftenutilized in high performance information handling systems. Therefore,the current invention provides an apparatus to incorporate SATA drivesinto fault-tolerant applications without the previously experiencedsingle point failure associated with SATA drives.

[0019] Referring now to FIG. 1, in a first embodiment of the presentinvention an apparatus for dual porting a serial disk drive 102, such asa SATA drive 104, is discussed. In the current embodiment, the dualporting apparatus 102 is included on a disk drive canister 114. Thepresent implementation allows for the utilization of the SATA drive 104in a fibre channel environment without the drawbacks associated withsingle point failures. In the present embodiment, the dual portingapparatus 102 is employed as part of the disk drive canister 114incorporated in an information handling system 100.

[0020] Furthermore, the arrangement of disk drive canister 114 includingassociated SATA drives 104 and dual porting apparatus 102 allows forredundancy in the information handling system 100, thus reducing therisk of a failure.

[0021] In the present embodiment, the dual porting apparatus 102 isconnected to a first and a second SATA master devices 110 & 112 througha back panel 106 of the information handling system 100 throughperipheral component interfaces (PCI) 108 implemented in the first andsecond SATA master devices 110 & 112. It is to be understood thatvarious interfaces may be employed as contemplated by one of ordinaryskill in the art without departing from the spirit and scope of thepresent invention, and it is the intention of the present invention toencompass and include these variations. For example the presentinterface may be incorporated in a proprietary bus or the like. Forpresent purposes the first and the second SATA master devices aresubstantially similar and are merely referred to as “first and second”SATA master devices 110 & 112 for convenience.

[0022] In the present embodiment, the first and second SATA masterdevices 110 & 112 individually include a fibre channel connection 116.Furthermore, the first and second SATA master devices include auniprocessor (uP) 118 and a memory 120.

[0023] Additionally, in the present embodiment the SATA master devices110 & 112 are capable of providing control signals from a higher levelto the dual porting apparatus 102 ensuring that only a single disk drivecanister 114 is enabled at a time. In further embodiments, the first andthe second SATA master devices 110 & 112 are continuously enabled withcontrols executed at a higher level guaranteeing that only a single SATAmaster device is enabled at a time. For example, by sending controlsignals from a higher level, switching in the middle of a command isprevented.

[0024] Referring now to FIG. 2, a disk drive canister 200 including adual porting apparatus 202 for porting a serial disk drive is discussed.In the present embodiment, the dual porting apparatus 202 may beconnected between a SATA disk drive 204 and the back panel of aninformation handling system, such as the arrangement discussed in FIG.1, thus effectively multiplexing the serial disk drive 204. In thecurrent embodiment the dual porting apparatus 202 is integrated in thedisk drive canister 200 thus allowing for ease of replacement in theevent of failure.

[0025] The present embodiment thus allows for the incorporation of theSATA disk drive 204 into a fault tolerant environment, such as fibrechannel based systems without the drawback of a single failure pointpreviously experienced with SATA drive included without the dual portingapparatus 202 of the present invention. Further, through implementationof the present invention the SATA drive 204 may continue to receive idlecharacters during utilization.

[0026] The dual porting apparatus 202 includes a first idle regenerator206. The first idle regenerator 206 is connected to a first serialmaster device, such as discussed in FIG. 1. The first idle regenerator206 in the present embodiment is capable of transmitting and receivingsignals to the first serial master device via an input/output connection208. In the current embodiment the input/output connection is madeutilizing a PCI, although it is contemplated that other interfaces arecapable of utilization for this purpose without departing from the scopeand spirit of the present invention. For example, the interface may beimplemented without a processor or be embodied in a proprietary bus, orthe like.

[0027] The dual porting apparatus 202 of the present embodiment furtherincludes a second idle regenerator 210. The second idle regenerator 210is connected to a second serial master device via input/outputconnection 212. The second serial master device of the presentembodiment is substantially similar to the second serial master deviceas discussed in FIG. 1. The second idle regenerator 210 is capable ofreceiving and transmitting signals to the second serial master device.Additionally, the second idle regenerator 210 is connected throughconnection 212 which is ported to the second serial master device thougha PCI.

[0028] A third idle regenerator 214 is connected to the first and thesecond idle regenerators 206 & 210 and additionally to the serial diskdrive 204. The third idle regenerator 214, included in the dual portingapparatus 202, is capable of transmitting and receiving signals from thefirst and second idle regenerators 206 & 210 and the serial disk drive204, such as a SATA disk drive.

[0029] Further included in the dual porting apparatus 202, issynchronization logic 216 connected to the first, second and third idleregenerators 206, 210 and 216 respectively. The synchronization logic216 is capable of synchronizing data transfers between one of the firstand second idle regenerators 206 & 210 and the third idle generator 214.For example, the synchronization logic 216 is capable of synchronizingthe third idle regenerator 214 with the second idle regenerator in theevent of a desired switch in data stream input from the first idleregenerator 206 to the second idle regenerator 210. Furthermore, shouldan event occur which causes a disruption in synchronization in the dualporting apparatus, the synchronization logic 216 is utilized toreestablish synchronization between the third idle regenerator and thefirst or second idle regenerator as required by the circumstances.

[0030] In embodiments of the present invention the dual portingapparatus 202 further includes an auto detector 218. The auto detector218 in the present embodiment is connected to the input/output of thefirst and the second serial masters devices 208 & 212, respectively aswell as the synchronization logic 216.

[0031] For example, the auto detector 218 may be incorporated into thedual porting apparatus 102 which in turn is included in a disk drivecanister 114 as discussed in FIG. 1 or the like. The auto detector 218is capable of automatically switching between the first and secondmaster devices based on the presence or absence of idle characterstransmitted by either of the first and second master devices. The autodetector 218 is further capable of controlling the switching between thefirst and second serial master devices, thus allowing the input/outputof data between the dual porting apparatus and one of the first andsecond master devices at a time.

[0032] In embodiments of the present invention the dual portingapparatus 202 is implemented as an application specific integratedcircuit (ASIC).

[0033] Referring generally to FIG. 3, in an alternative embodiment adual porting apparatus 302 may be capable of being switched between thefirst and the second serial master devices through control signals sentfrom an external source, such as a SATA master device.

[0034] It is believed that the DUAL PORTING SERIAL ATA DISK DRIVES FORFAULT TOLERANT APPLICATIONS of the present invention and many of itsattendant advantages will be understood by the forgoing description. Itis also believed that it will be apparent that various changes may bemade in the form, construction and arrangement of the components thereofwithout departing from the scope and spirit of the invention or withoutsacrificing all of its material advantages. The form herein beforedescribed being merely an explanatory embodiment thereof. It is theintention of the following claims to encompass and include such changes.

What is claimed is:
 1. An apparatus for dual porting a serial diskdrive, comprising: a first idle regenerator connected to a first serialmaster device, the first idle regenerator being capable of receiving andtransmitting signals to the first serial master device including an idlecharacter stream; a second idle regenerator connected to a second serialmaster device, the second idle regenerator being capable of receivingand transmitting signals to the second serial master device including anidle character stream; a third idle regenerator connected to the serialdisk drive and the first and second idle regenerators, wherein the thirdidle regenerator is capable of communicating with the serial disk driveand the first and second idle regenerators; and a synchronization logiccapable of synchronizing data transfers between one of the first idleregenerator and the second idle regenerator, and the third idlegenerator, wherein the synchronization logic is connected to the first,the second and the third idle regenerators.
 2. The apparatus for dualporting a serial disk drive of claim 1, further comprising, an autodetector connected to the first and the second idle regenerators,wherein the auto detector is capable of controlling data transfers tothe first and the second idle regenerators based on the presence of idlecharacters from the first and the second serial master devices.
 3. Theapparatus for dual porting a serial disk drive of claim 2, wherein theauto detector is capable of switching between the first and the secondserial masters.
 4. The apparatus for dual porting a serial disk drive ofclaim 3, wherein the auto detector enables communication with a singleserial master at a time.
 5. The apparatus for dual porting a serial diskdrive of claim 1, wherein the dual porting apparatus is suitable forutilization with a serial advanced technology attachment disk drive. 6.The apparatus for dual porting a serial disk drive of claim 1, whereinthe dual porting apparatus is suitable for utilization with fibrechannel based communication.
 7. The apparatus for dual porting a serialdisk drive of claim 1, wherein the synchronization logic is capable ofproviding synchronization for idle character switching.
 8. The apparatusfor dual porting a serial disk drive of claim 1, wherein the dualporting apparatus is embodied in an application specific integratedcircuit.
 9. The apparatus for dual porting a serial disk drive of claim1, wherein the dual porting apparatus is integrated with the serial diskdrive.
 10. An apparatus for dual porting a serial disk drive,comprising: a first idle regenerator connected to a first serial masterdevice, the first idle regenerator being capable of receiving andtransmitting signals to the first serial master device including an idlecharacter stream; a second idle regenerator connected to a second serialmaster device, the second idle regenerator being capable of receivingand transmitting signals to the second serial master device including anidle character stream; a third idle regenerator connected to the serialdisk drive and the first and second idle regenerators, wherein the thirdidle regenerator is capable of communicating with the serial disk driveand the first and second idle regenerators; a synchronization logiccapable of synchronizing data transfers between one of the first idleregenerator and the second idle regenerator, and the third idlegenerator, wherein the synchronization logic is connected to the first,the second and the third idle regenerators; and an auto detectorconnected to the first and the second idle regenerators, wherein theauto detector is capable of controlling data transfers to the first andthe second idle regenerators based on the presence of idle charactersfrom the first and the second serial master devices.
 11. The apparatusfor dual porting a serial disk drive of claim 10, wherein the dualporting apparatus is suitable for utilization with a serial advancedtechnology attachment disk drive.
 12. The apparatus for dual porting aserial disk drive of claim 10, wherein the auto detector enablescommunication with a single serial master at a time.
 13. The apparatusfor dual porting a serial disk drive of claim 10, wherein the dualporting apparatus is suitable for utilization with fibre channel basedcommunication.
 14. The apparatus for dual porting a serial disk drive ofclaim 10, wherein the synchronization logic is capable of providingsynchronization for idle character switching.
 15. The apparatus for dualporting a serial disk drive of claim 10, wherein the dual portingapparatus is embodied in an application specific integrated circuit. 16.The apparatus for dual porting a serial disk drive of claim 10, whereinthe dual porting apparatus is integrated with the serial disk drive. 17.An apparatus for dual porting a serial disk drive, comprising: a firstmeans for regenerating an idle character stream, connected to a firstserial master device, wherein the first idle generating means is capableof transmitting and receiving signals to and from the first serialmaster device; a second means for regenerating an idle character stream,connected to a second serial master device, wherein the second idlegenerating means is capable of transmitting and receiving signals to andfrom the second serial master device; a means for communicating serialdisk drive data connected to the serial disk drive, the drivecommunication means being connected to the first and the second idledata stream means, wherein the drive communication means is capable ofgenerating an idle data stream; and a means for synchronizingcommunications between the first and the second idle regenerating meansand the disk drive communication means.
 18. The apparatus for dualporting a serial disk drive of claim 17, further comprising an automaticdetector means capable of controlling the enabling of the first and thesecond idle regenerating means based on the presence of idle characters.19. The apparatus for dual porting a serial disk drive of claim 18,wherein the automatic control means enables a single idle regenerationmeans at a time.
 20. The apparatus for dual porting a serial disk driveof claim 17, wherein the apparatus is suitable for utilization with aserial advanced technology attachment disk drive.
 21. The apparatus fordual porting a serial disk drive of claim 17, wherein the dual portingapparatus is suitable for utilization with fibre channel basedcommunication.
 22. The apparatus for dual porting a serial disk drive ofclaim 17, wherein the apparatus is embodied in an application specificintegrated circuit.
 23. An apparatus for dual porting a serial advancedtechnology attachment disk drive for utilization in fibre channel basedcommunication, comprising: a first idle regenerator connected to a firstserial master device, the first idle regenerator being capable ofreceiving and transmitting signals to the first serial master deviceincluding an idle character stream; a second idle regenerator connectedto a second serial master device, the second idle regenerator beingcapable of receiving and transmitting signals to the second serialmaster device including an idle character stream; a third idleregenerator connected to the serial disk drive and the first and secondidle regenerators, wherein the third idle regenerator is capable ofcommunicating with the serial disk drive and the first and second idleregenerators; a synchronization logic capable of synchronizing datatransfers between one of the first idle regenerator and the second idleregenerator, and the third idle generator, wherein the synchronizationlogic is connected to the first, the second and the third idleregenerators; and an auto detector connected to the first and the secondidle regenerators, wherein the auto detector is capable of controllingdata transfers to the first and the second idle regenerators based onthe presence of idle characters from the first and the second serialmaster devices.
 24. The apparatus for dual porting a serial disk driveof claim 23, wherein the auto detector enables communication with asingle serial master at a time.
 25. The apparatus for dual porting aserial disk drive of claim 23, wherein the dual porting apparatus isembodied in an application specific integrated circuit.
 26. Theapparatus for dual porting a serial disk drive of claim 23, wherein thedual porting apparatus is integrated with the serial disk drive.